Examine source code of Readsy

{
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{934cc649-75cc-412f-94a4-20a73ec45081}"
    }
  },
  "name": "Readsy",
  "description": "A tool to help users read text more easily by highlighting key parts of speech",
  "version": "1.0.1",
  "icons": {
    "16": "/images/logo_16.png",
    "48": "/images/logo_48.png",
    "128": "/images/logo_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "externally_connectable": {
    "ids": [
      "*"
    ],
    "matches": [
      "https://readsyapp.com/*",
      "https://www.readsyapp.com/*",
      "https://readsy.app/*",
      "http://readsyapp.com/*",
      "http://www.readsyapp.com/*"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "jquery.js",
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "web_accessible_resources": [
    "popup.html",
    "/images/logo_pic.png",
    "/images/cog.svg",
    "/images/xcircle.svg"
  ]
}